No, you don't need to do anything like shave or clip your hair unless you doctor specifically asked you to. Most of the time I will use clips if needed, or frankly, the assistant is there to help with holding the hair in place. There's no need for you to be concerned and try to prep.
"This answer has been solicited without seeing this patient and cannot be held as true medical advice, but only opinion. Seek in-person treatment with a trained medical professional for appropriate care."